The present invention relates to dampers, and in particular, to dampers for rotatable bodies. Various components for machines such as fans, gas turbine engines, and other systems used on aircraft or elsewhere can experience undesirable vibrations. A particular component can have one or vibrating more modes, or harmonics, that would be excited by conditions the component is expected to experience during operation. Such vibration can undesirably cause the vibrating component, or other components in the machine, to operate incorrectly or even fail completely.
Various techniques can be used to dampen modal vibrations. However, in applications where space is limited and adding mass is undesirable, it can be difficult to suitably dampen the vibrations within the space limitations without hindering performance of the vibrating component in particular or of the machine in general. This problem can be especially difficult when the vibrating component is a body that rotates, such as a cylinder.